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Re: Scope Creep

2008-04-02 03:32:03

Dave Crocker writes:
John Leslie wrote:
   I'm happy to call it "registration" too. I think this should tend
to get us thinking about the right thing. How should the intent to
receive email for a domain be signaled?

The current model permits no email-specific registration, in order to operate a mail-receiving service. Anything that eliminates use of an A/AAAA record changes this basic flexibility.

So the requirement "How should the intent to
> receive email for a domain be signaled?" is, in fact, a very basic change to the core Internet mail service model.

If the ability to set up a mail server purely by setting up a host (without adding an MX record) is a significant feature of the internet mail system, then I would expect to see significant use of it. Right?

So I took 30,000 recent messages containing little spam. In those messages I found 954 unique domains in To, From, Cc and Reply-To fields. Among the 954 domains, practically all have MX records and most have A records. There are 38 domains that have an A record but no MX. All 38 are reachable, 33 answer on port 80, 21 answer on port 25, and some of the 21 seem to be incorrectly configured.

So that leaves about 20 domains, 2% of the original.

Yes, it's a basic feature, but it's a little-used one, and half the usage is due to mistakes. _Half_ the users won't get their DSNs. That's not a feature we ought to extend to IPv6.

In a clean-slate exercise, there are good reasons to consider imposing that requirement. In a world with decades of momentum for administering and operating email a certain way, changing the registration model warrants separate, careful, and extended consideration.

It is a topic thoroughly worthy of that consideration.

However, trying to squeeze that effort into the RFC2821bis process is a good way to kill both.

It would be good to have wording for 2821bis that neither consciously extends the A rule nor consciously doesn't extend it. But I can't think of a way to do it.

Arnt

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